The present invention relates to an expansion joint seal of the type used for sealing an expansion gap against the intrusion of dirt, water and other debris, as for example might be encountered by expansion joints in a pedestrian walkway or concourse. More specifically, the present invention relates to an elastomeric expansion seal adapted to be positioned between a pair of spaced-apart, structural slab members or the like; and wherein the seal is of the type having substantially vertically disposed sidewalls, an upper treadway surface and a lower surface, and an internal webbing structure permitting the seal to expand and contract with contraction and expansion of the structural members to which it is affixed.
Seals of this general type are known in the art. The seal of the present invention is suitably modified to be especially suited for sealing structural members that may have relatively larger size gaps therebetween.
One of the problems associated with expansion seals for large gapsor those having relatively high width to height ratios is that of maintaining an adequate sealing pressure between the side edges of the seal and the respective contacting side edges of the structural slab members when the seal is at or near its maximum position of expansion in response to expansion of the gap due to changing environmental or structural conditions or the like.
Another related problem is the prevention of buckling or collapsing of the seal as the same is made larger in width relative to its height.
It is also desirable, especially in concourse or walkway expansion joints, to maintain the degree of vertical seal "growth" as small as possible as the same moves to its contracted position in response to contraction of the gap such that the upper surface stays relatively flush with the walkway surface thereby to avoid tripping or the like which may be caused by uneven surfaces.